Centrifugal casting method

ABSTRACT

This invention relates to a method of making mortar or concrete pipes by centrifugal casting. The method is characterized by using mortar or concrete prepared from a cementiteous material incorporated with a salt of Beta -naphthalenesulfonic acidformaldehyde condensate, and curing the mortar or concrete pipes made by the above condition with high pressure steam in an autoclave.

i-7Z XR 3967695 1 v v --'w vwuwvu l "Ivv'lllv Nishi et a1. 45 July 11,1972 s41 CENTRIFUGAL CASTING METHOD 3,277,162 10/1966 Johnson ..106/90[72] Inventors: Sci" Nkhi; Akin Osho, both of Tokyo; 2,690,975 10/ 1954Scripture... ..106/315 Kl omits no Kawa uchi all 0H3 an 2,499,445 3/1950Ammann -.106/315 g p 2,141,571 12/1938 Kennedy et al... .....106/90 [731Assignees: Onodn Cement Company Limited, Onoda- 2,141,569 12/ 1938Tucker 106/90 shi, Yamaguchi; Nippon Concrete Indus- 1.972,208 9/1934Tucker 106/90 tries C Limited, T k J 22 F] d Se :32 OTHER PUBLICATIONS 1I: p" Taylor, W. H., Concrete Technology and Practice," Amer- PP' N0570,599 ican Elsevier, pgs. 339- 340 (1965).

Primary xaminer--Tobias E. Levow [30] Foreign Application HornyAssistant Examiner-W. T. Scott Sept. 9, 1969 Japan ..44/71016Attorney-Fidelman, Wolffe & Leitner [52] US. Cl. ..264/234, 106/90,106/95, [57] ABSIRACT [51] In. CL f F 106,3 This invention relates to amethod of making mortar or [58] Field oiSearch ..1os/9o,9s, 314 315'264/234 by mum is cham' 264/311 tenzed by using mortar or concreteprepared from a cementiteous material incorporated with a salt of B-naphthalenesulfonic acid-formaldehyde condensate, and cur- [56]References Cited ing the mortar or concrete pipes made by the abovecondition UNITED STATES p -rs with high pressure steam in an autoclave.

3,465,825 9/1969 Hook et a1. ..106/90 16 Claims, No Drawings CENTRIFUGALCASTING METHOD This invention relates to a method of making mortar orconcrete pipes, such as piles, poles or Hume pipes, by centrifugalcasting.

On making green mortar or concrete pipes by centrifugal casting process,a small amount of cement, sand and impalpable powder additives arebrought to the inside surface of a cast pipe by water segregated out ofmortar or concrete during casting. As the result a separate layer ofslurry is formed. For instance, although use of fine silica, fly ash orblast furnace slag as an irnpalpable miscible material brings about suchadvantages that the water-impermeability of the mortar or concrete pipeis enhanced, the production cost is reduced and the increment inmechanical strength by autoclave curing is increased, it promotes theformation of a layer of segregated slurry on the inside wall of the pipeand the formed layer gradually deforms eventually to give a very uneveninside surface for the inside wall of the pipe when the revolution ofthe casting machine was stopped. The formation of such a layer ofsegregated slurry is undesirable because it causes not only lowering ofthe strength of the product but also increase in frictional resistanceagainst pass of a liquid through the product pipes.

In our experiments, mortar pipes were cast with mortars having flowvalues of 170 180 mm. The mortars were prepared by mixing a mixture ofnonnal Portland cement and fine silica in an amount of 40 percent of thetotal weight (Blaine value 3750 cmlg, specific gravity 2.68) with riversand and adding to the mixture as a water reducing agent a sodium saltof fl-NS-fonnaldehyde condensate containing at least SB-NS units in amolecule, Maginon 100 supplied by Sugai Chemical Industry Co., Ltd. ofwhich the main ingredient is calcium alkylaryl-sulfonate, Pozzolith No.5L supplied by Nisso-Masterbuilders Co., Ltd. of which the mainingredient is calcium lignin-sulfonate or mixture of such a waterreducing agent with either Plastirnent supplied by Nippon Sika K.K. ofwhich the main ingredient is a sodium salt of adipic acid derivatives orcalcium lactate in an aqueous solution in the amounts as listed in theTable l. Fourteen kgs of the mortar was cast in a spinning machine tomake a pipe (outer diameter cm, inner diameter 12 cm, length cm) whilerevolving the machine at an initial speed of 150 rpm for 1.5 minutes, atan intermediate speed of 300 rpm for 1.5 minutes and a final speed of550 rpm for 4 minutes and the thickness of a layer of segregated slurryin the inside wall of the pipe was determined. The results weresummarized in the Table 1. In these experiments there was used sand ofthe Kinu-gawa river 25 (maximum gram size 5 mm, FM=3.1).

TABLE 1 Dimlnution in percentage of water/cement Water/cementWater/cement ratio Thickness mounts Water Amounts ratio (w/c)1 ratio(wk-)2 or layer of Water reducing added reducing added Flow immediatelyalter consoli- Segregated agent (percent) agent (percent) (mm.) altermixing dation (w/c)l slurry (mm.) 170 0. 383 0. 343 0. 104 7-9 170 0.347 0. 341 0. 017 8-10 178 0. 336 0. 324 0. 033 7- 0 179 0.320 0. 265 0.171 0 0. 03 180 0. 383 0. 345 0. 105 8-10 0. 06 175 0.368 0. 325 0. 1178-10 0. 12 180 0. 349 0. 303 0. 132 6-7 0. 03 180 0. 380 0. 340 0. 1068-10 0. 06 175 0.383 0. 342 0.110 8-10 0.12 170 0.388 0. 342 0.119 8-100. 03 180 0. 352 0. 296 0. 159 0 0. 06 180 0. 349 0. 262 0. 250 0 1t 15an ob ect of the present invention to provide a'method Note:

of making well consolidated mortar or concrete pipes without formationof such a layer of segregated slurry on the inside wall of pipes.

Another object is to obtain mortar or concrete pipes having higherstrength.

It has now been discovered that these objects are attained by use of amortar or concrete added a water reducing agent comprising a salt offl-naphthalenesulfonic acid (hereinafter referred to asp-NS")-formaldehyde condensate represented by the formula 2 CHI8-B BOsNa S OrN nl where n is a number of greater than 2.

to Portland cement. or a mixture of Portland cement and an impalpablemiscible material such as fine silica, fly ash, blast furnace slag orthe like (these cements will hereinafter be referred to as "cementiteousmaterials"). The mortar or concrete thus prepared is formed into a pipeby centrifugal casting and subjected it to high pressure steam curing orto steam curing and then after remolding, to high pressure steam curingin an autoclave. It has also been found that the necessary amount of theabove condensate added to cementiteous materials can be reduced by usingthe above condensate in combination with a water reducing agent such ascarboxylic acids and hydroxy carboxylic acids. The term "water reducingagent" used in this specification means an agent which reduces thenecessary amount of water to form a concrete or mortar of desiredworkability.

H: Sodium salt of B-NS-formaldehyde condensate containing 5 or more B-NSunits in a molecule.

A: Plastiment.

N: Calcium lactate (extra pure reagent).

The above Table l indicates that in case of the plain mortar containingfine silica, the segregation of an impalpable miscible material is of ahigh degree, in case where a sodium salt of fi-NS-formaldehydecondensate alone is added, the segregation of an irnpalpable misciblematerial decreases in proportion of increase in the amount added andcome nearer to zero in the amount of 0.75 percent, in cases where eitherPlastiment or calcium lactate alone is added, the segregation of animpalpable miscible material is reduced little in proportion of increasein the amount added, and when the sodium salt of NS-formaldehydecondensate is used in combination with the Plastiment or calcium lactatethe segregation of an impalpable miscible material is reduced 1 v zeroin a smaller amount of the former.

The present invention bases itself on the above discoveries and residesin a method of making mortar or concrete pipes by centrifugal castingwhich is characterized by adding a salt of fl-NS-formaldehyde condensatecontaining 5 or more fi-NS units in a molecule either alone or incombination with a carboxylic acids, hydroxy carboxylic acids, theirderivatives, al-

ble materials such as fine sili (fly ash last furnace slag or the like.

.kali or alkaline earth metal salts thereof to mortar or concrete As thesalt of B-NS-formaldehyde condensate preferably used in the practice ofthe present invention are sodium-, calciumand their mixed salts ofB-NS-formaldehyde condensates containing at least 70 percent ofcondensation polymers having 5 to B-NS units in a molecule. Thecarboxylic acids and hydroxy carboxylic acid suitably used compriselactic acid, gluconic acid, adipic acid, succinic acid, maleic acid,heptanoic acid, and their derivatives, alkali and alkaline earth metalsalts thereof, and mixtures thereof are also used.

The salt of B-NS-formaldehyde condensate may be added in the amount of0.75 to 1.5, preferably 0.8 to 1.2 percent by weight of cementiteousmaterials when used alone, and in the amount of 0.2 to 1.5, preferably0.4 to 1.2 percent weight of cementiteous materials when used incombination of the carboxylic acids, hydroxylic carboxylic acids, theirderivatives, alkali or alkaline earth metal salts thereof or mixturethereof which may be used in the amount of 0.03 to 0.2, preferably 0.06to 0.15 percent by weight of cementiteous materials.

According to the present invention the segregation of slurry comprisingcement and an impalpable miscible material during pipe casting isavoided and, thereby, well-consolidated mortar or concrete pipes aremanufactured in a simple way at a moderate cost.

EXAMPLE 2 Concretes were prepared by adding coarse aggregate and fineaggregate in the amounts as listed in Table 3 to 500 kg/cm" of acementiteous material (mixture of 450 kg/m of normal Portland cement and50 leg/cm of fly ash of Blaine value of 3100 cmlg) and then a'sddiuniorc al i m salt of B- NS-formaldehyde condensate (5-l0B-NS units in amolecule) (H) or (H'), Plastiment (A). calcium lactate (L), sodiumsuccinate (S), sodium gluconate (G), sodium maleate (M) and water in theamounts as listed in the Table 3. The concretes thus obtained were castin a spinning machine to make pipes while revolving the machine at aninitial speed of 100 rpm for 1.5 minutes, at an intennediate speed of310 rpm for 1.5 minutes and a final speed of 380 rpm for 4 minutes, andgreen concrete pipes (outer diameter cm. inner diameter 18cm, length10cm) were made. The thickness of a layer of segregated slurry in theinside wall of the pipes was shown in Table 3.

The green concrete pipes thus obtained were cured at 180 C for 5 hrs inan autoclave. After curing, compressive strength of pipes wasdetennined. The results obtained were summarized in Table 3.

TABLE 3 Unit aggregate Compressive content (kg/m9) strength UnitWater/cement Layer 0t after Water Amounts Water Amounts water ratio(w/c) segregated autoclave reducing added reducing added content Below5-20 Slump immediately slurry curing agent (percent) agent (percent)(kgJmJ) 5 mm. mm. (cm.) after mixing (mm.) (kg/em!) 0.5 60 730 1090 7 0.331 7-10 843 0. 75 740 1158 20 0.270 0-2 1050 0.5 A 0.1 44 740 1116 70.288 0 922 0.5 L 0.06 750 1117 10 0.280 0 904 0.5 S 0.06 38 750 1121 50.276 0 900 0.5 G 0.15 40 750 1117 11 0.280 2 898 0.5 M 0.15 38 750 11215 0.276 2 910 40 EXAMPLE 1 What is claimed is:

Concretes were prepared by adding coarse aggregate and fine aggregate inthe amounts as listed in the Table 2 to 600 Kg/m of a cementiteousmaterial (mixture of 4150 Kg/m of normal Portland cement and 150 Kg/m"of fine silica of Blaine value of 3,800 cm /g) and then a sodium salt offl-NS-formaldehyde condensate (5 to 10 B-NS units in a molecule),Plastiment and water in the amounts as listed in the Table 2. Theconcretes thus obtained were cast into pipes by means of the spinningmachine as used in the above experiments on the manufacture of mortarpipes under the same conditions as in the above experiments. The resultswere summarized in the Table 2.

the group consisting of sodium and calcium salts.

3. The method of claim 1 wherein said condensate comprises at leastpercent condensation polymers having at least five B-naphthalenesulfonicacid units in a molecule.

TABLE 2 Diminution in percentage uilgioillfiga%gat0 o1 waterl Thicknesscement rat. 0 of 1a or Unit (kg/m3) Water/cement Water/cement ofsegrentor Amounts Water Amounts water ratio (wlc)1 ratio (w/c): )o gatediuem added reducing added content Below 5-20 Slump immediately aftercensolislurry agent. (percent) agent (percent) (kg/m3) 5 mm. mm. (cm.)after mixing datiou (V/O1 (mm Plain concrete 3 598 1 0 6 0.355 0.3320.065 7-10 11 203 001 1,'oa7 7 0.334 0.334 0.065 7-9 162 tilli 1, 008 200. 270 (l. 227 0. 1.50 2 103 014 1,051 7 0.322 0.273 0.152 0 Note:

Symbol H and A have the same meanings as in the Table 1. The above Table2 indicates that according to the present invention concrete pipes areobtained without or with little fonnation of a layer of segregated layerin the inside wall of a pipe.

4. The method of claim 1 wherein said salt is present in an amount offrom 0.8 to 1.2 by weight based on the cementitious material.

5. The method of claim 1 wherein said cementitious material is selectedfrom the group consisting of Portland cement and mixtures of Portlandcement and a material selected from the group consisting of fine silica,fly ash, and blast furnace slag.

6. The method of claim 1 wherein said cast pipes are subjected to highpressure steam curing in an autoclave.

7. In a method of making cementitious pipe by centrifugal casting, theimprovement which comprises adding from 0.2 to 1.5 percent weight of asalt of a B-naphthalenesulfonic acidforrnaldehyde condensate and from0.03 to 2 percent weight of any member selected from the groupconsisting of carboxylic acids, hydroxy carboxylic acids, derivativesthereof, and alkali and alkaline earth metal salts thereof, to thecementitious material prior to casting, the weight percent being basedon the cementitious material.

8. The method of claim 7 wherein said condensate comprises at least 70percent condensation polymers having at least five B-naphthalenesulfonicacid units in a molecule.

9. The method of claim 7 wherein said condensate is present in an amountof from 0.4 to 1.2 percent by weight.

10. The method of claim 7 wherein said member is present in an amountfrom 0.06 to 0.15 percent by weight.

11. The method of claim 10 wherein said condensate is present in anamount of from 0.4 to 1.2 percent by weight.

12. The process of claim 7 wherein said member is selected from thegroup consisting of lactic acid, gluconic acid, adipic acid, succinicacid, malleic acid, heptanedioic acid, and alkali metal salts, alkalineearth metal salts and derivatives thereof.

13. The method of claim 12 wherein said condensate com prises at least70 percent condensation polymers having at least fiveB-napthalenesulfonic acid units.

14. The method of claim 13 wherein the member is a sodium salt of anadipic acid derivative.

15. The method of claim 13 wherein the member is calcium lactate.

16. The method of claim 7 wherein the cast pipes are subjected to highpressure steam curing in an autoclave.

* i i i l

2. The method of claim 1 wherein said salt is selected from the groupconsisting of sodium and calcium salts.
 3. The method of claim 1 whereinsaid condensate comprises at least 70 percent Condensation polymershaving at least five Beta -naphthalenesulfonic acid units in a molecule.4. The method of claim 1 wherein said salt is present in an amount offrom 0.8 to 1.2 by weight based on the cementitious material.
 5. Themethod of claim 1 wherein said cementitious material is selected fromthe group consisting of Portland cement and mixtures of Portland cementand a material selected from the group consisting of fine silica, flyash, and blast furnace slag.
 6. The method of claim 1 wherein said castpipes are subjected to high pressure steam curing in an autoclave.
 7. Ina method of making cementitious pipe by centrifugal casting, theimprovement which comprises adding from 0.2 to 1.5 percent by weight ofa salt of a Beta -naphthalenesulfonic acid-formaldehyde condensate andfrom 0.03 to 2 percent by weight of any member selected from the groupconsisting of carboxylic acids, hydroxy carboxylic acids, derivativesthereof, and alkali and alkaline earth metal salts thereof, to thecementitious material prior to casting, the weight percent being basedon the cementitious material.
 8. The method of claim 7 wherein saidcondensate comprises at least 70 percent condensation polymers having atleast five Beta -naphthalenesulfonic acid units in a molecule.
 9. Themethod of claim 7 wherein said condensate is present in an amount offrom 0.4 to 1.2 percent by weight.
 10. The method of claim 7 whereinsaid member is present in an amount from 0.06 to 0.15 percent by weight.11. The method of claim 10 wherein said condensate is present in anamount of from 0.4 to 1.2 percent by weight.
 12. The process of claim 7wherein said member is selected from the group consisting of lacticacid, gluconic acid, adipic acid, succinic acid, malleic acid,heptanedioic acid, and alkali metal salts, alkaline earth metal saltsand derivatives thereof.
 13. The method of claim 12 wherein saidcondensate comprises at least 70 percent condensation polymers having atleast five Beta -napthalenesulfonic acid units.
 14. The method of claim13 wherein the member is a sodium salt of an adipic acid derivative. 15.The method of claim 13 wherein the member is calcium lactate.
 16. Themethod of claim 7 wherein the cast pipes are subjected to high pressuresteam curing in an autoclave.